Headphone



FIG. 1 is a perspective view of a headphone, showing our design;

FIG. 2 is front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a side view thereof;

FIG. 5 is an opposing side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines showing the environment are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a headphone, as shown and described. 